Wire tensioning apparatus



March 3, 1970 R. a. LANGE ETAL WIRE TENSIONING APPARATUS Filed April 29,1968 INVENTORS ROLLAND B. LANGE GEORGE E. DAKE Jr. BY

MXM

United States Patent 3,498,516 WIRE TENSIONING APPARATUS Rolland B.Lange, North Muskegon, and George E. Dake, Jr., Muskegon, Mich.,assignors to Anaconda Wire and Cable Company, a corporation of DelawareFiled Apr. 29, 1968, Ser. No. 724,869 Int. Cl. B65b 23/08 US. Cl. 2261953 Claims ABSTRACT OF THE DISCLOSURE A friction grip for applying tensionto strands of magnet wire being paid from a stationary coil is rotatablymounted so that it will turn freely to follow the twisting of the wire.

Background of the invention In the handling of wires and other strandsit is commonly required to pay a wire endwise from a stationary coileven though the wire may have some degree of torsional stiffness. Thecoil from which the wire is being paid may or may not be wound on aflanged reel. Paying the wire thus, instead of unwinding it from arotating reel, introduces a 360 twist into the wire for each convolutionthat is paid off. In coil winding machines and other applications thistwist may, in itself, be unobjectionable, but it is usually necessary totension, or brake a wire as it pays from a coil and for this purpose itis passed through some device that applies friction to the wire surface.In some cases the friction is applied by passing the wire betweenopposing soft surfaces such as felt and in other cases the surfaces maybe hard and highly polished such as tungsten carbide. Whatever thenature of the friction surface, however, tensioning devices of this typehave been a universal source of trouble in the form of wire damage anddefective coil forming and no completely satisfactory wire tensioner hasbeen available.

Summary We have now discovered that the basis of the poor performance ofprior art wire tensioners for strand being paid from stationary coilsresides in the fact that the twist in the wire is pushed back as itpasses through the friction member. Thus twists are accumulated untilthe wire breaks or enough torsional stress develops to spurt a tightgroup of twists through the tensioner. In the case of insulated magnetwire the torsion may crack or weaken the insulation and in all cases theuneven torsional distribution may produce an erratic movement in thewire leaving the tensioner. We have now overcome this problem bymounting the friction applying member so that it can rotate very freelyaround the wire axis. For this purpose we have invented an apparatus fortensioning an advancing wire comprising a stationary frame with meansfor guiding the wire through the apparatus. Our frame may convenientlycomprise a base plate and two apertured plate members extending normallyfrom it. Bearing means are supported on the frame such as by beingmounted in one of the plate members. Our apparatus comprises frictionmeans, such as opposing elongated pads, engaging the strand. Thefriction means is freely rotatable around the axis of advance of thestrand, and may be mounted 3,498,516 Patented Mar. 3, 1970 on a hollowshaft that is rotatably supported in the hearing means.

Brief description of the drawing The figure shows a pictorial view of anembodiment of our invention.

Description of the preferred embodiment In the drawing our tensioningapparatus, indicated generally by the numeral 10 comprises a frame 11built to include a horizontal base plate 12 from which extend verticalplates 13 and 14 with respective apertures 16, 17. Within the aperture16 there is mounted a ball bearing 18 within the inner race of whichthere is fitted a hollow stub shaft 19. Brazed to the arms 21, 23respectively are channels 24, 25 into which are inserted felt pads 26,27 through which tension is to be applied. Adjustable pressure isapplied to the pads 25, 26 by means of a threaded pin 29 and compressionspring 31. A wire guide consisting of a perforated plastic cylinder 32fitted into a sleeve 33 is mounted in the aperture 17. As the wire 28passes between the pads 26, 27 the entire assembly mounted on the stubshaft 19 rotates in the bearing 18 as may be required to follow theturning of the wire with each convolution that pays from a coil, notshown. It will be understood that, although we have illustrated afriction device with felt pads which have particular application forenamelled magnet wire other friction devices may be used, particularlywhere there is no danger of damaging the wire surface. Pads of materialssuch as leather, foam rubber, nylon, fluorocarbons, polished carbides,and the like may also find application in the practice of our invention.It is important however that the friction applying member shall be freeto rotate, and to rotate continuously in one direction, soas toaccommodate the twisting of wire being pulled from a coil.

Although our invention has particular application to solid wires becausethey are usually stiffer in torsion than stranded wires, it is by nomeans limited thereto, provided that a stranded wire presents theproblem hereinabove discussed, and wires of materials other than metal,such as plastic, and glass may also be tensioned with apparatus made toour invention.

We have invented a new and useful apparatus of which the foregoingdescription has been exemplary rather than definitive and for which wedesire an award of Letters Patent as defined in the following caims.

We claim:

1. Apparatus for tensioning an advancing wire being paid from astationary coil comprising:

(A) a stationary frame,

(B) means guiding said wire through said apparatus,

(C) bearing means supported on said frame, and

(D) friction means engaging said strand,

(a) said friction means being mounted in said bearing means, and

(b) said friction means being freely rotatable around the axis ofadvance of said wire.

2. The apparatus of claim 1 wherein said friction means comprisesopposing elongated pads, said wire advancing between said pads and saidapparatus comprising means urging said pads against said wire.

3. The apparatus of claim 2 wherein said frame comprises a base plate,and two apertured plate members extending normally from said base plate,said wire ad vancing through apertures in said members, said bearingmeans being mounted in one of said apertures and guiding means for saidWire being mounted in the other of said apertures, said apparatuscomprising a hollow shaft, said shaft being rotatably supported in saidbearing means, and said pads being fastened to said shaft.

References Cited UNITED STATES PATENTS 1,793,092 2/1931 Jesperson242-149 3,112,899 12/1963 Hosbein 242147 X ALLEN N. KNOWLES, PrimaryExaminer US. Cl. X.R. 226-198; 242-149

